Cheesy Au Gratin Potatoes

Cheesy Au Gratin Potatoes are pure cheesy, creamy, melt-in-your-mouth deliciousness! Thinly sliced potatoes are layered here with flavorful onion, minced garlic and topped with a gruyere, cheddar, and parmesan cheese sauce. Easy to make and absolutely delicious to eat, it’s the ultimate Thanksgiving side!  


  • 6 medium sized white potatoes, thinly sliced
  • 1 yellow onion, sliced
  • 35 garlic cloves, minced
  • 1/4 cup butter, salted
  • 1/4 cup all purpose flour
  • 2 1/2 cups milk, warm
  • 1 1/4 cup cheddar cheese, shredded
  • 1 1/4 cup gruyere cheese, shredded
  • 3/4 cup parmesan cheese, shredded
  • salt & pepper
  • fresh thyme


  1. Set the oven to 350 degrees.
  2. Next thinly slice the potatoes & onion and mince the garlic cloves.
  3. Line the potatoes slices up in three rows down the center of a large baking dish, almost like horizontal stacks.  Place the onion slices in between the potato slices, making sure they are evenly dispersed throughout the whole dish.  Spread the minced garlic on top and add salt & pepper.  Set aside.
  4. Next work on your cheese sauce.  Start by melting the butter and flour together on the stove in a pan over medium heat.  Cook for a couple of minutes until it starts to turn golden in color and creates a slightly nutty smell.
  5. Then add the warm milk to the flour & butter in an even stream.  Whisk constantly while doing this.  Then continue to whisk for about another 5 minutes, while the sauce thickens up.
  6. Once the sauce has thickened, turn the heat to low and add in the shredded cheese – 1 cup cheddar, 1 cup gruyere, 1/2 cup parmesan.  I recommend you use block cheese that you shred yourself!  Continue whisking until the cheese melts and a creamy sauce forms.  Add salt & pepper to taste.
  7. Then pour the cheese sauce on top of the potatoes and spread evenly.
  8. Top with the remaining 1/4 cup of each of the cheeses.
  9. Bake for 60 minutes.
  10. Enjoy!

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